The regular expression enforces the following rules:
* Must be at least 10 characters
* Must contain at least one one lower case letter, one upper case letter, one digit and one special character
* Valid special characters (which are configurable) are - @#$%^&+=

^(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{4,8}$

Password matching expression. Password must be at least 4 characters, no more than 8 characters, and must include at least one upper case letter, one lower case letter, and one numeric digit.